kdiff 0.3.1

Changed

• The runtime's three hot paths — comparison, application and tracking — allocate substantially less
  for the same results. No API is removed or changed, no annotation means anything different, and the
  change vocabulary is untouched: upgrading is a version bump.

  Comparison builds a lifted path in one copy instead of two and lifts a nested collection change once
  instead of twice; sets are compared by membership rather than by building two intermediate sets; a
  keyed list indexes by key without wrapping every element, and detects a repeated key from that index
  rather than from a second walk. Applying returns a property no change addresses as the source
  instance rather than rebuilding it. Tracking resolves each property's depth once when the scope is
  resolved, so deciding whether to report a change allocates nothing. Routing groups changes once
  instead of scanning them once per handler.

• Applying a diff no longer rebuilds a property that nothing in the change list addresses: the source
  instance is carried through, as it already was for a nested value and for a property excluded from
  comparison. Results compare equal either way; what changes is that the rebuilt object now shares an
  untouched collection with its source, exactly as copy() already did for every property a patcher
  does not name.

  The one precondition this does not skip is a keyed list holding a repeated key, which is still
  rejected whether or not a change addresses it.

• A generated apply declares the set of compared property names once as a private property instead
  of rebuilding it on every call, and gathers its failures into one list instead of folding them with
  +. The generated API is unchanged — the new property is private — but regenerating is needed to
  pick this up.

Added

• kdiff-benchmarks, an unpublished module carrying JMH benchmarks for comparison, application,
  tracking and routing. It is deliberately not part of ./gradlew check; run it with
  ./gradlew :kdiff-benchmarks:jmh, adding -Pjmh.profilers=gc for allocation rate.